Surgical insertion instruments

ABSTRACT

A surgical instrument includes a shaft having a distal end connectable with an implant, and a handle connected to a proximal end of the shaft. The instrument defines an internal fluid channel through which a fluid can be passed. A kit includes the instrument and a spinal implant that is expandable through the introduction of the fluid therein. A method of using the instrument includes passing a fluid through an internal fluid channel defined by the instrument and toward the implant.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of the filing date of U.S.Provisional Patent Application No. 62/319,460 filed Apr. 7, 2016, thedisclosure of which is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present inventions relate to surgical instruments used during theinsertion of spinal implants and methods of using such instruments. Moreparticularly, the present inventions relate to instruments capable ofpassing a fluid through an internal fluid channel thereof and into animplant to cause expansion of the implant.

Intervertebral implants are commonly used in spinal surgery, such as ininterbody fusion procedures, in which an implant (e.g., a spacer orcage) is placed in the disc space between two vertebrae to be fusedtogether. At least a portion of the disc is typically removed before theimplant is positioned in the intervertebral space, and the implant maybe supplemented with bone graft material to promote fusion of thevertebrae. Interbody fusion procedures may also be performed inconjunction with other types of fixation, such as pedicle screwfixation, to provide additional stability, particularly while thevertebrae fuse together.

Different interbody fusion procedures can be distinguished by theirlocation along the spine (e.g., in the cervical, thoracic, or lumbarregions); by the type of implant used; and by the surgical approach tothe intervertebral space, in which different surgical approaches oftenimply different structural characteristics of the implant or implantsused. Different surgical approaches to the spine include anterior,posterior, and lateral. Examples of interbody fusion techniquesperformed along a posterior approach include posterior lumbar interbodyfusion (PLIF) and transforaminal lumbar interbody fusion (TLIF). PLIFtechniques typically include positioning two intervertebral implantsinto the intervertebral space along a posterior to anterior direction,with one implant being positioned towards the left side of the spine andone implant being positioned towards the right side of the spine. Theimplants used in such PLIF techniques typically have a straight shape,in that they extend along a central axis. TLIF techniques, by contrast,typically include positioning one intervertebral implant into theintervertebral space (often towards the anterior portion of theintervertebral space) from the posterior of the patient, but the spineis approached on one side from a more lateral position than in PLIFtechniques. The implants used in such TLIF techniques are often curved,such that they have an overall kidney bean-like shape.

Included among the different types of intervertebral implants areexpandable implants. Such implants often have an initially contractedconfiguration, such that they have a low profile in thesuperior-inferior direction, in order to ease insertion into theintervertebral space. Such expandable implants can then be expanded inthe superior-inferior direction after implantation, so as to securelyengage and stabilize the vertebrae on both sides of the intervertebralspace. Examples of such expandable intervertebral implants are disclosedin U.S. Pat. No. 8,992,620, which is hereby incorporated by referenceherein as if fully set forth herein.

Insertion of an expandable implant requires one or more instrumentscapable of inserting an implant to its final destination within the discspace, typically based on one of the aforementioned approaches, andexpanding the implant during or after insertion. Examples of suchinstruments are disclosed in U.S. Pat. No. 8,998,924, which is herebyincorporated by reference herein as if fully set forth herein.

Although considerable effort has been devoted in the art to optimizationof such instruments and methods, still further improvement is desirable.

BRIEF SUMMARY OF THE INVENTION

A first aspect of the present invention is a surgical instrumentincluding a shaft having a distal end connectable with an implant, and ahandle connected to a proximal end of the shaft, wherein the instrumentdefines an internal fluid channel through which a fluid can be passed.

In accordance with other embodiments of the first aspect, the internalfluid channel may include a cavity in the handle, and the handle mayinclude an aperture in a proximal portion of the handle that is incommunication with the cavity. The handle may include a movable valveconfigured to seal the cavity at the aperture. The surgical instrumentmay further include a plunger movable within the cavity to force fluidfrom the aperture to a distal portion of the cavity. The plunger mayhave an externally threaded section. The handle may include a togglehaving an internally threaded section configured to selectively engagethe externally threaded section of the plunger. When the toggle is in anengaged position, the plunger may only move within the cavity byrotating the plunger to engage the externally threaded section of theplunger with the internally threaded section of the toggle. When thetoggle is in a disengaged position, the plunger may move freely withinthe cavity. The toggle may include opposing first and second toggleclips. The toggle clips may be spring biased to the engaged position.

The surgical instrument may further include a tubular duct having aproximal end configured to connect to the instrument to communicate withthe internal fluid channel and a distal end configured to connect to thedistal end of the shaft to allow passage of a fluid from the internalfluid channel to the implant. The proximal end of the tubular duct maybe at least partially disposed within a passage of the handle. The shaftmay include a recessed passage in which a portion of the tubular ductcan be disposed. The tubular duct may be configured to move along theshaft within the recessed passage. The proximal end of the tubular ductmay be at least partially disposed within a passage of the shaft. Thetubular duct may include a wire disposed within a tube, wherein the wireis movable between a proximal position and a distal position, the wirebeing configured to cooperate with a mechanism of the implant when inthe distal position. The wire may be spring biased to the proximalposition. The surgical instrument may further include a gauge incommunication with the fluid channel and configured to indicate pressurewithin the fluid channel, wherein the gauge is movable within a gaugecavity in the handle and can be advanced to move the wire from theproximal position to the distal position. The surgical instrument mayfurther include a collapse shaft movable within a cavity in the handle,wherein the collapse shaft can be advanced to move the wire from theproximal position to the distal position.

The surgical instrument may further include a gauge in communicationwith the fluid channel and configured to indicate pressure within thefluid channel The handle may extend along an axis that is angled withrespect to an axis along which the shaft extends. The surgicalinstrument may further include a rod disposed within at least a portionof the shaft and having a threaded distal end for attaching to theimplant.

A second aspect of the present invention is a kit including a spinalimplant and a surgical instrument including a shaft having a distal endconnectable with an implant, and a handle connected to a proximal end ofthe shaft, wherein the instrument defines an internal fluid channelthrough which a fluid can be passed. In accordance with anotherembodiment of the second aspect, the spinal implant may be expandablethrough the introduction of the fluid therein.

A third aspect of the present invention is a method of using a surgicalinstrument including steps of connecting an implant to a distal end of ashaft of the instrument, the instrument including a handle connected toa proximal end of the shaft, and passing a fluid through an internalfluid channel defined by the instrument and toward the implant.

In accordance with other embodiments of the third aspect, the method mayfurther include a step of loading the fluid into a cavity of theinternal fluid channel that is disposed in the handle. The step ofloading the fluid may include introducing the fluid through an apertureof the handle that is in communication with the cavity. The step ofloading may further include moving a valve of the handle away from theaperture. The method may further include a step of advancing a plungerwithin a cavity of the internal fluid channel that is disposed in thehandle to force the fluid distally in the cavity. The step of advancingmay include threading the plunger into the cavity. The step of advancingmay further include engaging an externally threaded section of theplunger with an internally threaded section of a toggle of the handle.The method may further include a step of actuating the toggle to adisengaged position so that the internally threaded section is not incommunication with the externally threaded section of the plunger andthe plunger can move freely within the cavity.

The method may further include steps of connecting a proximal end of atubular duct to the instrument and into communication with the internalfluid channel, and connecting a distal end of the tubular duct to thedistal end of the shaft, wherein the tubular duct allows passage of thefluid from the internal fluid channel to the implant. The method mayfurther include a step of passing the fluid through the internal fluidchannel, through the tubular duct, and into the implant to expand theimplant. The step of connecting the proximal end of the tubular duct mayinclude placing at least a part of the proximal end within a passage ofthe handle. The method may further include a step of placing a portionof the tubular duct in a recessed passage of the shaft. The method mayfurther include a step of allowing the tubular duct to move along theshaft within the recessed passage. The step of connecting the proximalend of the tubular duct may include placing at least a part of theproximal end within a passage of the shaft. The method may furtherinclude a step of advancing a wire disposed within a tube of the tubularduct to a distal position to cooperate with a mechanism of the implant.The step of advancing the wire may cause the implant to reduce in size.The step of advancing the wire may include advancing a gauge incommunication with the fluid channel to indicate pressure within thefluid channel to move the wire to the distal position. The step ofadvancing the wire may include advancing a collapse shaft to move thewire to the distal position. The method may further include a step ofthreading a rod disposed within at least a portion of the shaft toattach a threaded distal end of the rod to the implant.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a surgical instrument including atube set in accordance with one embodiment of the present invention.

FIGS. 2-4 are a first side elevational view, a top view, and a secondside elevational view, respectively, of the instrument shown in FIG. 1.

FIG. 5 is a front perspective view of a shaft of the instrument shown inFIG. 1.

FIG. 6 is a rear view of the instrument shown in FIG. 1.

FIG. 7 is a rear perspective view of the shaft of the instrument shownin FIG. 1.

FIG. 8 is a front perspective view of a distal end of the shaft of theinstrument shown in FIG. 1.

FIG. 9 is a side sectional view of a distal end of the shaft of theinstrument shown in FIG. 1.

FIG. 10 is a side sectional view of a portion of the instrument shown inFIG. 1.

FIG. 11 is a side elevational view of an implant collapse shaft of theinstrument shown in FIG. 1.

FIG. 12 is a side elevational view of a driver of the instrument shownin FIG. 1.

FIG. 13 is a side sectional view of a handle of the instrument shown inFIG. 1.

FIG. 14 is a side elevational view of a gauge of the instrument shown inFIG. 1.

FIGS. 15 and 16 are side sectional views of the gauge shown in FIG. 14.

FIGS. 17 and 18 are side sectional views of the handle of the instrumentshown in FIG. 1 used with a syringe extension.

FIG. 19 is a side elevational view of the syringe extension shown inFIG. 17.

FIGS. 20 and 21 are side sectional views of a proximal portion of thehandle of the instrument shown in FIG. 1 used with a plunger.

FIG. 22 is a bottom sectional view of a proximal portion of the handleof the instrument shown in FIG. 1.

FIG. 23 is a bottom sectional view of a proximal portion of the handleof the instrument shown in FIG. 1 used with a plunger.

FIGS. 24 and 25 are side elevational and top sectional views,respectively, of the plunger shown in FIG. 23.

FIGS. 26 and 27 are side and top elevational views, respectively, of atube set of the instrument shown in FIG. 1.

FIGS. 28 and 29 are side and top elevational views, respectively, of asurgical instrument including in accordance with another embodiment ofthe present invention.

FIG. 30 is a rear view of the instrument shown in FIG. 28.

FIG. 31 is a rear view of just the handle of the instrument shown inFIG. 28.

FIG. 32 is a side sectional view of the instrument shown in FIG. 28taken along the line 32-32 of FIG. 30.

FIG. 33 is a side sectional view of the instrument shown in FIG. 28taken along the line 33-33 of FIG. 30.

FIG. 34 is a portion of a side sectional view of the instrument shown inFIG. 28 taken along the line 34-34 of FIG. 31.

FIGS. 35 and 36 are top plan views of the instrument shown in FIG. 28.

FIG. 37 is a top sectional view of a distal portion of the instrumentshown in FIG. 28.

FIGS. 38 and 39 are top plan views of a distal portion of the instrumentshown in FIG. 28.

FIG. 40 is a top sectional view of a distal portion of the instrumentshown in FIG. 28.

FIGS. 41 and 42 are side sectional views of a proximal portion of thehandle of the instrument shown in FIG. 28 used with a plunger.

FIG. 43 is a side sectional view of a proximal portion of the handle ofthe instrument shown in FIG. 28.

FIG. 44 is a side sectional view of a proximal portion of the handle ofthe instrument shown in FIG. 28 used with a plunger and a driver.

FIG. 45 is a side sectional view of a portion of the handle of theinstrument and a tube set shown in FIG. 28.

FIG. 46 is a side sectional view of a proximal portion of the handle ofthe instrument shown in FIG. 28 used with a tool.

FIGS. 47-49 are front, rear, and side perspective views, respectively,of a surgical instrument in accordance with another embodiment of thepresent invention.

DETAILED DESCRIPTION

In describing the preferred embodiments of the subject illustrated andto be described with respect to the drawings, specific terminology willbe used for the sake of clarity. However, the invention is not intendedto be limited to any specific terms used herein, and it is to beunderstood that each specific term includes all technical equivalentsthat operate in a similar manner to accomplish similar purpose.

As used herein, when referring to bones or other parts of the body, theterm “proximal” means closer to the heart and the term “distal” meansmore distant from the heart. The term “inferior” means toward the feetand the term “superior” means towards the head. The term “anterior”means towards the front part of the body or the face and the term“posterior” means towards the back of the body. The term “medial” meanstoward the midline of the body and the term “lateral” means away fromthe midline of the body.

A first embodiment of a surgical instrument 100 is depicted in FIGS.1-26. Instrument 100 is bayoneted such that it includes a shaft 110 thatextends along an axis that is angled with respect to an axis along whicha handle 140 extends, as shown in FIGS. 1, 2, and 4. This allows for thedistal portion of instrument 100 to be utilized at a surgical site whilehandle 140 is disposed outside of the direct line of site of the distalportion while in use to improve visualization through an accessinstrument, such as a retractor or tube used in MIS procedures. Thebayoneted configuration of instrument 100 allows for the length of shaft110 to be offset from handle 140 and aid in visualization. It alsoallows room for an impaction surface 117 on the proximal end of aproximal portion 112 of shaft 110 if the user desires a more inlineimpaction than that provided on the back of handle 140, as shown inFIGS. 6 and 7.

As shown more clearly in FIGS. 1-4, a distal portion 111 of shaft ismonolithically constructed with the rest of shaft 110. Distal portion111 of shaft 110 has a face 113 from which a threaded rod 114 of a drawrod 119 protrudes. Rod 114 can be engaged with a threaded hole of asurgical implant to secure such implant to instrument 100 at face 113.Such a surgical implant is shown and described in U.S. ProvisionalPatent Application No. 62/319,513 filed on Apr. 7, 2016, entitledExpandable Interbody Implant, the disclosure of which is herebyincorporated by reference herein as if fully set forth herein. Ananti-rotation feature 115 also protrudes from face 113 and isdimensioned to mate with a corresponding feature of the surgical implantto prevent rotation and maintain a substantially static connectionbetween instrument 100 and the surgical implant during a surgicalprocedure. Flanges 127 are disposed on either side of face 113 to moreaccurately match the curve of the implant to make the connection flush.

A tube set 182 is shown connected with instrument 100 in FIGS. 1, 9, and10. Tube set 182, which is depicted alone in FIGS. 26-28, is the duct orconduit through which saline is passed from handle 140 to the surgicalimplant. It includes a flexible tube 183, a distal exit port 184 with ano-ring 185 or seal, and a proximal attachable end 186 having an o-ring187 or seal. Proximal attachable end 186 can be loaded into a port inshaft 110 such that the aspects of tube set 182 located proximally ofo-ring 187 are in communication with the saline delivery system withinshaft 110 and handle 140. Tube set 182 further includes an unlock wire188 made of nitinol and having a proximal knob 189, which is separatedfrom a proximal end of proximal attachable end 186 via a spring 190. Thecontours of knob 189 and the open areas of spring 190 allow saline topass through or around them to enter and travel through flexible tube183. The dimensions of unlock wire 188 are such that saline can flowaround and past unlock wire 188 within flexible tube 183 to ultimatelyflow out of distal exit port 184 and into a connected implant.

As shown in FIG. 9, distal exit port 184 is configured to be attachedwithin distal end 111 of shaft 110 so that it is positioned to engage aportal of the surgical implant. More specifically, as shown in FIG. 8,tube set 182 is located within a recessed passage 116 of shaft 110 sothat distal exit port 184 is exposed at face 113 of distal portion 111of shaft 110. O-ring 185 of tube set 182 allows for a sealed connectionwith the implant. Unlock wire 188 extends through distal exit port 184.Distal movement of knob 189 of unlock wire 188 causes distal movement ofunlock wire 188 within flexible tube 183 so that it can cooperate with amechanism of the implant to collapse the implant, as explained furtherbelow. In its resting state, spring 190 can maintain unlock wire 188 ina proximal position. Spring 190 provides resistance when moving unlockwire 188 distally.

As shown in FIG. 7, at a proximal end of proximal portion 112 of shaft110, an aperture 118 provides access to the proximal end of draw rod119, which is connected with threaded rod 114. The proximal end of drawrod 119 includes a non-circular head through which a correspondinginstrument can be used to rotate draw rod 119 along its axis, whichactuates threaded rod 114 to engage the surgical implant. Theconfiguration of the proximal end of draw rod 119 can be a square head(as shown), a hex head, or the like. Draw rod 119 is preferablyremovably positioned within shaft 111 and monolithically connected withthreaded rod 114.

Also at a proximal end of proximal portion 112 of shaft 110, an aperture120 provides access to unlock wire 188 of tube set 182. Aperture 120includes an internal threaded portion 121 that can cooperate withexternal threads on an implant collapse shaft 122, shown in FIGS. 10 and11. Implant collapse shaft 122 can be advanced distally within aperture120 via engagement by a driver 123, shown in FIG. 12, in a non-circulardriver keyway 128 of implant collapse shaft 122. When advanced, a distalend of implant collapse shaft 122 engages knob 189 of tube set 182 toadvance unlock wire 188 distally. Through rotation, the threads allowfor advancing and retracting unlock wire 188 in a more precise mannerThe engagement between implant collapse shaft 122 and driver 123 can bea hex head, square head, or the like. Threaded portion 121 of aperture120 can also be connected with a slap hammer or strike plate to assistwith inserting or removing an attached implant with respect to theintervertebral space. A distal end of threaded portion 121 provides adepth stop for inserting implant collapse shaft 122 only to a particulardepth. Implant collapse shaft 122 also has an o-ring 126 at a distal endthereof to prevent backflow of saline and to maintain a seal in theinternal passage system of instrument 100, which is described furtherbelow.

As shown in FIGS. 2 and 4, windows 125 on both sides of shaft 110 canreveal a position of implant collapse shaft 122 to identify its locationwithin shaft. A mark denoted with a “C” located at a distal end ofwindow 125 is aligned with the proximal end of implant collapse shaft122 when unlock wire 188 is in position to collapse the surgicalimplant. A mark denoted with an “X” located at a proximal end of window125 is aligned with the proximal end of implant collapse shaft 122 whenunlock wire 188 is in position to allow expansion of the surgicalimplant. Alternately, different identifiers may be used for expanded andcollapsed positions, and other positions could be identified as well.

Draw rod 119 and tube set 182 provide a dual shaft system in that theyrun in parallel down the length of shaft 110, as shown in FIGS. 9 and10. Draw rod 119 is offset from the saline delivery line in which tubeset 182 is disposed to allow for optimal wall thickness and strengththroughout the instrument 100. Draw rod 119 is recessed below animpaction surface 117 at a proximal end of shaft 110.

Handle 140 is rigidly connectable with proximal portion 112 of shaft110. This connection can be permanent or removable, though it isconfigured to be rigidly maintained during a surgical procedure.Instrument 100 utilizes a rigid threaded connection which provides theuser a stable and consistent means of insertion. The rigid connectionalso allows for a more reliable seal between the implant and theinstrument 100. In removable configurations of instrument 100, somecomponents can be sterilized such as by autoclaving and reused with newversions of other replaceable components.

Handle 140 includes a grip portion 141 at which a user can hold handle140. As shown in FIGS. 1, 2, 4, 22, and 23, a toggle 142 is a two-piecestructure located at a proximal end of handle 140 and is used to engageand disengage a syringe plunger 160, shown in FIGS. 20-25. Toggle 142communicates with a cylindrical cavity 144 within handle 140. Plunger160 extends into cylindrical cavity 144 of handle 140 and can becontacted by threaded inner surfaces 145 of toggle 142. Toggle 142 canmove between an engaged position (shown in FIG. 23) and a disengagedposition (shown in FIG. 22). In the engaged position, the threaded innersection 145 toggle 142 engages an externally threaded section includingthreads 161 of plunger 160. In this engaged position, plunger 160 canonly move within cylindrical cavity 144 by being rotated to advance orretract it. In the disengaged position, the inner surfaces 141 of toggle142 are disengaged from threads 161, allowing plunger 160 to move freelyto be advanced or retracted within cylindrical cavity 144 simply due toforce applied to plunger 160 along its axis. This allows for a morerapid insertion and release of plunger 160 within cylindrical cavity144. Toggle 142 includes two toggle clips, one on each side of handle140. The toggle clips can be moved by simply pushing proximal surfacesthereof, which pivots the threaded inner surfaces 145 away from eachother. Toggle 142 is maintained in its engaged position by springs 139.

Cylindrical cavity 144 of handle 140 is part of an internally fluidchannel of instrument 100 that is configured to hold saline or anotherfluid, which can be passed through instrument 100 into the surgicalimplant to facilitate expansion of the implant. Plunger 160 is themechanism by which the saline is forced toward the surgical implant.Care must be taken while expanding the implant within an intervertebraldisc space so as not to cause trauma to the patient. With this in mind,rotation of plunger 160 when toggle 142 is in its engaged positionallows for precisely controlled translation of plunger 160 withincylindrical cavity 144, which therefore allows for a preciselycontrolled amount of saline to be displaced toward the implant. Whenneeded, toggle 142 can be moved to its disengaged position to allow fora more rapid insertion of saline, or for a more rapid removal of plunger160 after a surgical procedure. Plunger 160 includes an integratedpressure relief valve to provide pressure relief when the pressureexceeds a certain value, such as 2000 psi. Under those circumstances,plunger 160 bleeds out any air or saline in the system. Also, whendisengaged from the implant, unlock wire 188 can be translated distallyto a location in which its distal end plugs distal exit port 184 toprevent leakage of saline from the system.

A valve 162 is positioned in handle to seal an aperture 163 of cavity144. Valve 162 is movable between a lowered position, as shown in FIG.20, in which cavity 144 is sealed, and a raised position, as shown inFIG. 21, in which access to cavity 144 is permitted. A tapered edge 164of valve 162 allows plunger 160 to encounter valve 162 and move it fromits lowered position to its raised position as plunger 160 is advancedinto cavity 144, which occurs via a cavity extension 165. Thisconfiguration allows for valve 162 to uncover aperture 163 only whenplunger 160 is present, which substantially prevents any leakage offluid from cavity 144 during the introduction and use of plunger 160.Valve 162 is biased to its lowered position through a spring (notshown).

Instrument 100 includes a network of passages through which saline cantravel toward tube set 182, and then through tube set 182 toward aconnected surgical implant at a distal end of distal portion 111 ofshaft 110. As shown in FIGS. 10 and 13, passages 151, 152, 153, and 154connect cylindrical cavity 144 with tube set 182 within which unlockwire 188 resides. The dimensions of unlock wire 188 and tube set 182 aresuch that saline can flow around and past unlock wire 188 to ultimatelyflow out of distal exit port 184 and into a connected implant. Whilepassage 151 is shown to be open at an external area of instrument 100,this allows for ease of manufacturing. That area can be plugged (asshown) or otherwise closed off to essentially close the passage so thatonly desired inlet and outlet portals exist within instrument 100.

As shown in FIGS. 13-16, a gauge 146 is integrated into the salinepassageway to allow for determining its internal pressure. Gauge 146 isremovable and is disposed within a channel 155 of handle 140 via achannel extension 166. External threads 147 on gauge 146 mate withinternal threads 148 of channel 155 to secure gauge 146 to handle 140. Aball 149 disposed within channel 155 mates with one of several detents156 of gauge 146 to provide tactile feedback that gauge 146 is seated tothe proper extent when it is inserted into channel 155. A distal end ofgauge 146 is open to allow saline to travel into gauge 146 via channels151 and 155. In other embodiments, gauge 146 can be a permanent part ofinstrument 100.

Gauge 146 has a color-coded end 157 that can protrude outwardlydepending on the magnitude of pressure within the passage system ofinstrument 100. Saline can enter gauge 146 through a lumen 158 at itsdistal end and then can communicate with a piston 159 that is connectedwith color-coded end 157. In this way, pressure in the internal fluidchannels can manifest itself into movement of piston 159 to exposecolor-coded end 157 to an appropriate degree that identifies the amountof pressure within the internal fluid channels. When greater pressureexists, gauge 146 protrudes to a particular extent to reveal a colorband through which the user can discern if a particular level ofpressure has been reached in instrument 100. Piston 159 can have o-rings168, 169 to prevent the fluid from moving past them within gauge 146.

The configuration of instrument 100 gives it an integrated design thatstreamlines the saline delivery as well as the pressure gauge into asingle inserter/handle combination. One component that is disposable andreplaceable is tube set 182. Plunger 160 and gauge 146 may also bedisposable in different embodiments that are not shown. The elements ofinstrument 100, such as shaft 110, can be made of stainless steel oranother biocompatible metal.

In use, instrument 100 facilitates insertion of an implant through anaccess instrument, such as a retractor or a tube used in MIS procedures.Instrument 100 is either assembled by the user or can come pre-assembledwith shaft 110 secured to handle 140 and draw rod 119 loaded into shaft110. Tube set 182 can also be preassembled or loaded by the user.Proximal attachable end 186 is loaded into a port in shaft 110, anddistal exit port 184 is attached within recessed passage 116 of shaft110 to expose distal exit port 184 at face 113. A flange 191 on aportion of proximal attachable end 186 fits into a slot withininstrument 100 during insertion into the port in shaft 110. The slot canbe linear to prevent rotation of proximal attachable end 186 within theport while still allowing for translation of proximal attachable end 186along its axis within the port for insertion and removal. In otherembodiments, the slot can be at least partially helical orcircumferential to temporarily locked proximal attachable end in place.Implant collapse shaft 122 is threaded into aperture 120 so thattogether, tube set 184 and implant collapse shaft 122 seal off theinternal passageway within shaft 110. This allows fluid from cavity 144to be passed entirely through tube set 184. When implant collapse shaft122 is first inserted, its marking is preferably aligned with theproximal mark of window 125 denoted with an “X” so that instrument 100is in a configuration to expand the implant.

Gauge 146 is connected to handle 140 by passing it through channelextension 166 and into channel 155. Gauge 146 is rotated to engageexternal threads 147 with internal threads 148 of channel 155, and isadvanced until ball 149 seats properly within one of detents 156.

A fluid, such as saline, is loaded into cylindrical cavity 144 of handle140. This is done by using a syringe filled with saline in conjunctionwith a syringe extension 167, as shown in FIGS. 17-19. Syringe extension167 includes an internal passage 170 and a mouth 171 to which thesyringe is connected. Syringe extension 167 is passed through cavityextension 165 to encounter and move valve 162 to its raised position, asdescribed above in connection with plunger 160. With internal passage170 in communication with cavity 144, the syringe is emptied to load thesaline into cavity 144. Additional saline can be provided and injectedwith the syringe until saline is produced at distal exit port 184 toensure that no air is present in the instrument's internal passage ortube set 182. Syringe extension 167 is then removed, allowing valve 162to move back to its lowered position to seal aperture 163 of cavity 144.Plunger 160 can then be introduced into cavity 144 the same way withtoggle 142 engaged.

An implant is secured to face 113 of shaft 110. This includes aligninganti-rotation feature 115 with a corresponding cavity in the implant,and threading threaded rod 114 into a threaded hole of a surgicalimplant by rotating draw rod 119 from its proximal end to draw theimplant flush against face 113. This positioning allows distal exit port184 to communicate with a port on implant so that saline can beintroduced into implant to facilitate expansion.

With the implant secured to instrument 100, the user can manipulatehandle 140 to position the implant into the desired location of the discspace. This can occur through an access instrument, such as one of 18 mmdiameter. During positioning, the user can impact surface 117 on theproximal end of proximal portion 112 of shaft 110.

Once in the desired position, the size of implant can be expandedthrough use of instrument 100. The user can locate toggle 142 in itsdisengaged position, if necessary, to more rapidly locate the plunger160 in its most efficient position. Alternatively, this could be donewhen the instrument is assembled or prepared so that plunger 160 will bein its starting position at this point when it is first needed. Toggle142 can then be moved to the engaged position so that plunger 160 can berotated to advance it within cylindrical cavity 144, which forces salineto travel through the passage system, including passages 151-154, andtube set 182, and into a cavity within the surgical implant. Thebayoneted shaft 110 improves visualization through the accessinstrument. Handle 140 is located away from the axis of the accessinstrument through which the procedure is performed, allowing greatervisualization along that axis.

During this procedure, saline travels toward the implant and also intochannel 155 to interact with gauge 146. Saline can enter lumen 158 bypassing around the distal end of gauge 146 in channel 155. The pressureexerted on piston 159 by the saline can cause color-coded end 157 toprotrude outward to indicate to the user via exposure of a color band asto the level of pressure that gauge 146 is reading. This allows the userto know if saline is being applied too rapidly or if the procedure iscomplete and the cavity in the implant is full. The main purpose ofpressure gauge 146 is to monitor safety and not exceed pressure to thenative tissue. When enough saline is passed, the user can move toggle142 to its disengaged position, and more rapidly remove plunger 160.

In a separate embodiment, the pressure gauge housing can be a clearrigid plastic with marking indicating the fluid volume for assessing therelative displacement of fluid via action of the plunger into theimplant, which could indicate incremental expansion of the implant.

If the surgeon wishes to collapse the implant during the procedure,implant collapse shaft 122 is threaded distally until the distal mark ofwindow 125 denoted with a “C” is aligned with the marking on implantcollapse shaft 122. This position may also coincide with implantcollapse shaft 122 abutting an internal surface of shaft 110 to preventfurther distal movement of unlock wire 188. In this configuration, theimplant can be collapsed from its expanded position. This is facilitatedby the distal end of unlock wire 188 engaging a mechanism of the implantthat releases a structure that otherwise maintains its expandedconfiguration. Collapsing or reducing the size of the implant typicallyincludes the saline disposed within the implant being passed back intoinstrument 100. Plunger 160 can be rotated proximally to allow thesaline back into instrument 100.

With the implant in its finally implanted (and preferably expanded)position, the implant can be disengaged from instrument 100. Thisincludes rotating draw rod 119 so that threaded rod 114 is drawn out ofthe threaded hole of the implant. Once disengaged from the implant,unlock wire 188 can be translated distally by unthreading implantcollapse shaft 122 to a location in which the distal end of unlock wire188 plugs distal exit port 184 to prevent leakage of any remainingsaline in the system. Instrument 100 can then simply be removed from thesurgical site. Plunger 160 can then be quickly removed from instrument100 by moving toggle 142 to its disengaged position. Tube set 184 canthen be removed and discarded so that the remaining components ofinstrument 100 can be sterilized for reuse.

A second embodiment of a surgical instrument 200 is depicted in FIGS.28-46. Instrument 200 is similar in its functionality with respect to asurgical implant, but it allows for different angles to be createdbetween the axis of instrument 200 and the axis of the surgical implant.Certain of the features of instrument 200 are similar to those ofinstrument 100, and accordingly, are like numbered.

Instrument 200 includes a shaft 210 and a handle 240 that togetherextend generally along a single axis. In other embodiments, instrument200 may be bayoneted. A distal portion 211 of shaft 210 has anintegrated junction block 270 that is pivotally connected with shaft210. A distal end of junction block 270 includes a face 213 from which athreaded rod 214 of a draw rod 219 protrudes through an aperture 278, asshown in FIGS. 37-40. Face 213 is configured to substantially match acurve of the corresponding implant to make the connection flush. Rod 214can be engaged with a threaded hole of a surgical implant. Ananti-rotation feature 215 is also disposed on face 213. A portal 271 isprovided through which a tube set can be connected, as discussed below.

Junction block 270 is connected with a rotatable housing 272 that isdisposed within a cylindrical cavity of distal portion 211 of shaft 210.This allows junction block 270 to rotate about the end of shaft 210within a slot 273 to different orientations with respect to the axis ofshaft 210, as shown in FIGS. 35 and 36. Draw rod 219 extends throughshaft 210 and rotatable housing 272. It can accommodate the differentangled positions of junction block 270 due to a U-joint 274 that allowsfor angles between threaded rod 214 and a proximal portion of draw rod219. Draw rod 219 is rotated via a tool 280, as shown in FIG. 46. Aproximal end of draw rod 219 can have a hex-head 281 or other geometricconfiguration that mates with tool 280. Tool 280 can be inserted througha threaded hole 295 at a proximal end of handle 240 to engage hex-head281, as shown in FIG. 46. Because tool 280 is not used simultaneouslywith plunger 260, valve 262 will be in its lowered position when tool280 is used so that valve 262 does not impede the use of tool 280.Threaded hole 295 can also be connected with a slap hammer or strikeplate to assist with inserting or removing an attached implant withrespect to the intervertebral space.

A proximal aspect of rotatable housing 272 has three facets 275 a-c thatcan mate with corresponding facets of a block 276 of shaft 210. Thefacets can be more or fewer in number, and can also be non-planar. Block276 is advanced along the axis of shaft 210 via its connection with ahollow cylinder 277 that is disposed in shaft 210 and within which drawrod 219 is disposed. A collar 279 of instrument 200 is disposed betweenshaft 210 and handle 240. Rotation of collar 279 translates hollowcylinder 277, thus moving block 276 to lock the tip angle. When block276 is moved proximally, a gap exists between block 276 and rotatablehousing 272, as shown in FIG. 38, allowing rotation of rotatable housing272 within shaft 210. When block 276 is moved distally as shown in FIG.39, the gap is closed and the facets are preferably engaged totemporarily secure the position of rotatable housing 272 within shaft210 and to prevent it from rotating. Threaded rod 214 can pivot from astarting angle (for example, an angle of about 20 degrees on one side ofthe axis of draw rod 219) through a final angle (for example, and angleof about 77 degrees on the other side of the axis of draw rod 219, i.e.through a total angular range of about 97 degrees). A laser mark and/orridge on collar 279 can align with a feature or mark on instrument 200to indicate when rotatable housing 272 is locked and/or unlocked. Inother embodiments, there are no mating facets between rotatable housing272 and block 276, and rotatable housing 272 and block 276 each haveround or curved surfaces that can mate and be locked by friction.

Cylindrical cavity 244 of handle 240 is configured to hold saline, asdiscussed above in connection with instrument 100. Saline is forcedthrough cylindrical cavity 244 by plunger 260, and then out throughpassages 251 and 254 that connect cavity 244 with a tube set 282.Plunger 260 can be the same plunger 160 configured to work with bothinstruments 100 and 200.

Tube set 282 can be identical to tube set 182 described above so that itcan be used with either of instruments 100 or 200. Proximal attachableend 286 can be loaded into a port, such as passage 254, in handle 240such that the aspects of tube set 282 located proximally of o-ring 287are in communication with the saline delivery system within handle 240.As shown in FIGS. 37-39, distal exit port 284 is configured to beattached within portal 271 of junction block 270. Thus, as junctionblock 270 rotates, distal exit port 284 rotates with it. Flexible tube283 of tube set 282 may have some slack to account for this rotation,and may also slide or otherwise move within recessed passage 216 alongshaft 210 to accommodate such movement of distal exit port 284. Passage216 has a groove and hook configuration to secure flexible tube 283while allowing movement of same therein. Proximal attachable end 286 canalso move within passage 254 during such movement, as shown in FIGS. 35and 36, while maintaining a seal with passage 254 due to o-ring 287. Aflange, similar to flange 191 discussed above, on a portion of proximalattachable end 286 fits into a slot within instrument 200 duringinsertion into the port in shaft 210. The slot can be linear to preventrotation of proximal attachable end 286 within the port and tofacilitate translation of proximal attachable end 186 along its axiswithin the port for insertion and removal and during operation ofinstrument 200, as described below.

As shown in FIGS. 43-45, a gauge 246 is integrated into the salinepassageway and is similar to that described above in connection withinstrument 100. Gauge 246 is removably disposed within a channel 255 ofhandle 240 via a channel extension 266 and threaded into place asdescribed above. In instrument 200, gauge 246 is in line with tube set282 such that a distal end of gauge 246 is in communication withproximal knob 289 of tube set 282, which is in turn connected with anunlock wire 288 and is separated from a proximal end of proximalattachable end 286 via a spring 290, as shown in FIG. 45. Gauge 246 canbe advanced distally within channel 255 via engagement by a driver 223,shown in FIG. 44. When advanced, a distal end of gauge 246 engages knob289 of tube set 282 to advance unlock wire 288 distally. Markings on anouter portion of handle 210, as shown in FIG. 28, can align with aportion or marking on gauge 246 when unlock wire 288 is in position tocollapse the surgical implant and when unlock wire 188 is in position toallow expansion of the surgical implant.

Handle 240 includes a toggle 242 and a valve 262 that are configuredsimilarly and operate similarly with their counterparts in instrument100 to interact with plunger 260.

In use, instrument 200 functions in a generally similar manner toinstrument 100. Instrument 200 can be provided pre-assembled or can beassembled by the user. This includes securing shaft 210 to handle 240and loading tube set 282 into handle 240 and junction block 270. Drawrod 219 can also be loaded into its respective channel. Gauge 246 isconnected to handle 240 in its working position. Cylindrical cavity 244of handle 240 can either be pre-loaded with saline, or cylindricalcavity 244 can be loaded with saline by the user in the same manner asdescribed above with respect to syringe extension 167.

Next, an implant is secured to face 213. This includes aligninganti-rotation feature 215 with a corresponding cavity in implant, andthreading threaded rod 214 into a threaded hole of the implant byrotating draw rod 219 from its proximal end to draw the implant flushagainst face 213. This positioning allows distal exit port 284,including o-ring 285, to communicate with a port on the implant so thatsaline can be introduced into implant to facilitate expansion.

With the implant secured to instrument 200, the user can manipulatehandle 240 through an access instrument, such as a retractor or a tube,to position the implant into the desired location of the disc space.During positioning, the user can impact the surface on the proximal endof handle 240. The implant and junction block 270 can be repositioned atthe end of shaft 210 to allow a user to more accurately access the discspace and position the implant in the proper and intended location inthe disc space. This may involve locking and unlocking the connectionbetween rotatable housing 272 (to which the implant is coupled) andblock 276 via rotation of collar 279. When locked, the facets ofrotatable housing 272 and block 276 may be aligned to prevent rotationof rotatable housing 272. When unlocked, rotation of the implant aboutthe distal portion of shaft 210 is allowed. The surgeon, at his or herdiscretion, can use this locking and unlocking feature to aid inachieving the desired final location of the implant.

Once in the desired position, the implant can be expanded through use ofinstrument 200. Toggle 242 can be moved to its engaged position withrespect to plunger 260. Plunger 260 can then be rotated to advance itwithin cylindrical cavity 244, which forces saline to travel out ofcylindrical cavity 244, through tube set 282, and into a cavity withinthe surgical implant. During this procedure, saline also travels throughchannel 255 and into communication with gauge 246 to advise or alert theuser via exposure of a color band, markings, or features as to the levelof pressure.

If the surgeon wishes to collapse the implant during the procedure,gauge 246 is threaded distally, which can be guided by aligning amarking or feature of gauge 246 with a mark on handle 240. This forcesknob 289 and thus nitinol wire 288 distally. In this configuration,instrument 200 is in a configuration in which the implant can becollapsed from its expanded position. This is facilitated by the distalend of nitinol wire 288 engaging a mechanism of the implant thatreleases a structure that otherwise maintains its expandedconfiguration. Plunger 260 can be rotated proximally to aid in drawingthe saline back into instrument 200. As gauge 246 is threadedproximally, spring 290 moves nitinol wire 288 back into its restingstate. The force exerted on knob 289 by gauge 246 is less than the forceof o-ring 287 within channel 255, so that movement of gauge 289 does notcorrespond with movement of proximal attachable end 286 within channel255.

With the implant in its final position, the implant can be disengagedfrom instrument 200. This includes rotating draw rod 219 so thatthreaded rod 214 is drawn out of the threaded hole of the implant.Instrument 200 can then simply be removed from the surgical site.

A third embodiment of a surgical instrument 300 is depicted in FIGS.47-49. Instrument 300 includes a handle 340 that is very similar inconfiguration and operation to handle 240 of instrument 200. Instrumentalso includes a shaft 310 that is very similar in configuration andoperation to shaft 110 of instrument 100. Instrument 300 does not have arotatable component at its distal end and is not bayonetted. Otherwise,the features and functions of instrument 300 are as described above inconnection with instruments 100 and 200.

Any of the present instruments 100, 200, and/or 300 can be provided in akit with a corresponding spinal implant, which is expandable through theintroduction of the fluid therein.

The instruments and the components thereof disclosed herein can be madeof any rigid biocompatible materials or combinations thereof, such as aplastic, PEEK, Radel, Silastic and any various grades of stainless steelfor medical application. The seals (o-rings or custom seals) can be madeof any biocompatible medical grade elastomeric materials with elasticproperties. For example, the gauge housing may be made of a transparentplastic. The syringe body may be made of a transparent plastic insertheld within the cavity of the handle with a side window for viewingfluid displacement.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

1. A surgical instrument comprising: a shaft having a distal endconnectable with an implant; and a handle connected to a proximal end ofthe shaft, wherein the instrument defines an internal fluid channelthrough which a fluid can be passed.
 2. The surgical instrument of claim1, wherein the internal fluid channel includes a cavity in the handle,and the handle includes an aperture in a proximal portion of the handlethat is in communication with the cavity.
 3. The surgical instrument ofclaim 2, wherein the handle includes a movable valve configured to sealthe cavity at the aperture.
 4. The surgical instrument of claim 2,further comprising a plunger movable within the cavity to force fluidfrom the aperture to a distal portion of the cavity.
 5. The surgicalinstrument of claim 4, wherein the handle includes a toggle having aninternally threaded section configured to selectively engage anexternally threaded section of the plunger.
 6. The surgical instrumentof claim 5, wherein when the toggle is in an engaged position, theplunger can only move within the cavity by rotating the plunger toengage the externally threaded section of the plunger with theinternally threaded section of the toggle, and when the toggle is in adisengaged position, the plunger can move freely within the cavity. 7.The surgical instrument of claim 5, wherein the toggle includes opposingfirst and second toggle clips.
 8. The surgical instrument of claim 5,wherein the toggle clips are spring biased to the engaged position. 9.The surgical instrument of claim 1, further comprising a tubular ducthaving a proximal end configured to connect to the instrument tocommunicate with the internal fluid channel and a distal end configuredto connect to the distal end of the shaft to allow passage of a fluidfrom the internal fluid channel to the implant.
 10. The surgicalinstrument of claim 9, wherein the proximal end of the tubular duct isat least partially disposed within a passage of the handle.
 11. Thesurgical instrument of claim 9, wherein the shaft includes a recessedpassage in which a portion of the tubular duct can be disposed.
 12. Thesurgical instrument of claim 11, wherein the tubular duct is configuredto move along the shaft within the recessed passage.
 13. The surgicalinstrument of claim 9, wherein the proximal end of the tubular duct isat least partially disposed within a passage of the shaft.
 14. Thesurgical instrument of claim 9, wherein the tubular duct includes a wiredisposed within a tube, wherein the wire is movable between a proximalposition and a distal position, the wire being configured to cooperatewith a mechanism of the implant when in the distal position.
 15. Thesurgical instrument of claim 14, wherein the wire is spring biased tothe proximal position.
 16. The surgical instrument of claim 14, furthercomprising a gauge in communication with the fluid channel andconfigured to indicate pressure within the fluid channel, wherein thegauge is movable within a gauge cavity in the handle and can be advancedto move the wire from the proximal position to the distal position. 17.The surgical instrument of claim 14, further comprising a collapse shaftmovable within a cavity in the handle, wherein the collapse shaft can beadvanced to move the wire from the proximal position to the distalposition.
 18. The surgical instrument of claim 1, further comprising agauge in communication with the fluid channel and configured to indicatepressure within the fluid channel
 19. The surgical instrument of claim1, wherein the handle extends along an axis that is angled with respectto an axis along which the shaft extends.
 20. A kit comprising: thesurgical instrument of claim 1; and a spinal implant that is expandablethrough the introduction of the fluid therein.